Apparatus for controlling the extraction duration in a laundry treating appliance

ABSTRACT

An apparatus for monitoring a characteristic of the motor for use in determining the duration of the extraction phase of the cycle of operation in a laundry treating appliance.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 12/964,004, filed Dec. 9, 2010, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

Laundry treating appliances, such as a washing machine in which a drumdefines a treating chamber for receiving a laundry load, may implementcycles of operation. The cycles of operation may include differentphases during which liquid is applied to the laundry load. The liquidmay be removed from the laundry load during an extraction phase wherethe drum is rotated at speeds high enough to impart a centrifugal forceon the load great enough to hold (a/k/a “plaster” or “satellize”) theload to the peripheral wall of the drum (the clothes rotate with thedrum and do not tumble) and extract liquid from the fabric items.Generally, the faster the rotation speed, the greater the centrifugalforce, and the greater the amount of liquid that can be extracted. Thisprocess is effective at removing excess liquid from the fabric items toprepare them to be dried.

SUMMARY OF THE INVENTION

In one aspect, a laundry treating appliance includes a rotatabletreatment chamber in which the laundry is received for treatment, amotor coupled to and rotating the treatment chamber, a motor torquesensor outputting a torque signal indicative of the motor torque, and acontroller having an extraction program comprising a plurality ofexecutable instructions stored in a memory of the controller, and thecontroller operably coupled to the motor and receiving the torquesignal. The controller controls the motor to implement the extractionprogram by rotating the treatment chamber through multiple, sequentiallyincreasing set spin speeds, which are at least a speed sufficient tosatellize laundry in the treatment chamber at each of the set spinspeeds, which results in a corresponding constant speed plateau wherethe treating chamber is rotated at a constant speed for thecorresponding set spin speed to define sequentially increasing constantspeed plateaus, ceasing the sequentially increasing speed plateaus whenthe set spin speed reaches a predetermined upper limit, monitoring thetorque signal indicative of motor torque during the speed plateaus,determining from the monitoring when the time rate of change of thetorque signal falls below a predetermined time rate of change thresholdvalue, and sequential advancement from a current one of the speedplateaus to the next one of the speed plateaus is triggered when thetime rate of change of the torque signal falls below the predeterminedtime rate of change threshold value for the current one of the speedplateaus.

In another aspect, a laundry treating appliance includes a rotatabletreatment chamber in which the laundry is received for treatment, amotor coupled to and rotating the treatment chamber, a moisture sensoroutputting a moisture signal indicative of the residual liquid retainedin the laundry, a motor torque sensor outputting a torque signalindicative of the motor torque, and a controller having an extractionprogram comprising a plurality of executable instructions stored in amemory of the controller, and the controller operably coupled to themotor and receiving the moisture signal and the torque signal. Thecontroller controls the motor to implement the extraction program byrotating the treatment chamber through multiple, sequentially increasingset spin speeds, which are at least a speed sufficient to satellizelaundry in the treatment chamber at each of the set spin speeds, whichresults in a corresponding constant speed plateau where the treatingchamber is rotated at a constant speed for the corresponding set spinspeed to define sequentially increasing constant speed plateaus, ceasingthe sequentially increasing speed plateaus when the moisture signalindicative of the residual liquid retained in laundry satisfies aresidual liquid threshold, monitoring the torque signal indicative ofmotor torque during the speed plateaus, determining from the monitoringwhen the time rate of change of the torque signal falls below apredetermined time rate of change threshold value, and sequentialadvancement from a current one of the speed plateaus to the next one ofthe speed plateaus is triggered when the time rate of change of thetorque signal falls below the predetermined time rate of changethreshold value for the current one of the speed plateaus.

In yet another aspect, a laundry treating appliance includes a rotatabletreatment chamber in which the laundry is received for treatment, amotor coupled to and rotating the treatment chamber, a motor torquesensor outputting a torque signal indicative of the motor torque, and acontroller having an extraction program comprising a plurality ofexecutable instructions stored in a memory of the controller, and thecontroller operably coupled to the motor and receiving the torquesignal. The controller controls the motor to implement the extractionprogram by rotating the treatment chamber through multiple, sequentiallyincreasing set spin speeds, which are at least a speed sufficient tosatellize laundry in the treatment chamber at each of the set spinspeeds, which results in a corresponding constant speed plateau wherethe treating chamber is rotated at a constant speed for thecorresponding set spin speed to define sequentially increasing constantspeed plateaus, ceasing the sequentially increasing speed plateaus aftera predetermined number of advancements, monitoring the torque signalindicative of motor torque during the speed plateaus, determining fromthe monitoring when the time rate of change of the torque signal fallsbelow a predetermined time rate of change threshold value, andsequential advancement from a current one of the speed plateaus to thenext one of the speed plateaus is triggered when the time rate of changeof the torque signal falls below the predetermined time rate of changethreshold value for the current one of the speed plateaus.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a sectional view of a laundry treating appliance according toone embodiment of the invention.

FIG. 2 is a schematic view of a control system of the laundry treatingappliance of FIG. 1.

FIG. 3 is a plot of drum speed verses time using the extraction methoddescribed in FIG. 3, graphing spin speed, motor torque, and extractedwater.

FIG. 4 is a flow chart illustrating an extraction method for controllingthe duration of an extraction phase of a cycle of operation according toan embodiment of the invention.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

The present invention relates generally to a laundry treating appliancethat monitors a characteristic of the motor used to determine theduration of the extraction phase of the cycle of operation. Morespecifically, the invention is related to controlling the duration ofextraction by rotating the treating chamber at a predetermined or setrotational speed until there is leveling of the motor torque.

FIG. 1 illustrates one embodiment of a laundry treating appliance in theform of a washing machine 10 according to one embodiment of theinvention. The laundry treating appliance may be any machine that treatsarticles such as clothing or fabrics. Non-limiting examples of thelaundry treating appliance may include a horizontal or vertical axiswashing machine; a horizontal or vertical axis dryer, such as a tumbledryer or a stationary dryer; a tumbling or stationaryrefreshing/revitalizing machine; an extractor; a non-aqueous washingapparatus; and a revitalizing machine. The washing machine 10 describedherein shares many features of a traditional automatic washing machine,which will not be described in detail except as necessary for a completeunderstanding of the invention.

While the washing machine 10 is illustrated as a horizontal-axis washingmachine, it is within the scope of the invention for the washing machine10 to be a vertical-axis washing machine. The invention is alsoapplicable to other laundry treating appliances where liquid isextracted by the rotation of the treating chamber. Non-limiting examplesof other laundry treating appliances include combination washer/dryers,dryers, and non-aqueous washing machines.

The washing machine 10 may include a cabinet 12 having a controller 14for controlling the operation of the washing machine 10 to complete acycle of operation. A user interface 16 on the cabinet 12 may includeone or more knobs, switches, displays, and the like for communicatingwith the user, such as to receive input and provide output.

A rotatable drum 18 may be disposed within the interior of the cabinet12 and defines a treating chamber 20 for treating laundry. The rotatabledrum 18 may be mounted within an imperforate tub 22, which is suspendedwithin the cabinet 12 by a resilient suspension system 24. The drum 18may include a plurality of perforations 26, such that liquid may flowbetween the tub 22 and the drum 18 through the perforations 26. The drum18 may further include a plurality of baffles 28 disposed on an innersurface of the drum 18 to lift the laundry load contained in the laundrytreating chamber 20 while the drum 18 rotates. Further, the drum 18 maybe coupled with a motor 30 having a stator 32 and a rotor 34 through adrive shaft 36 for selective rotation of the treating chamber 20 duringa cycle of operation. It is also within the scope of the invention forthe motor 30 to be coupled with the drive shaft 36 through a drive beltfor selective rotation of the treating chamber 20.

The motor 30 may rotate the drum 18 at various speeds in oppositerotational directions. In particular, the motor 30 can rotate the drum18 at speeds to effect various types of laundry load movement inside thedrum 18. For example, the laundry load may undergo at least one oftumbling, rolling (also called balling), sliding, satellizing (alsocalled plastering), and combinations thereof. During tumbling, thefabric items in the drum 18 rotate with the drum 18 from a lowestlocation of the drum 18 towards a highest location of the drum 18, butfall back to the lowest location before reaching the highest location.Typically, the centrifugal force applied by the drum to the fabric itemsat the tumbling speeds is less than about 1 G. During satellizing, themotor 30 may rotate the drum 18 at rotational speeds wherein the fabricitems are held against the inner surface of the drum and rotate with thedrum 18 without falling. This is known as the laundry being satellizedor plastered against the drum. Typically, the force applied to thefabric items at the satellizing speeds is greater than or about equal to1 G. For a horizontal axis washing machine 10, the drum 18 may rotateabout an axis that is inclined relative to the horizontal, in which casethe term “1 G” refers to the vertical component of the centrifugal forcevector, and the total magnitude along the centrifugal force vector wouldtherefore be greater than 1 G. The terms tumbling, rolling, sliding andsatellizing are terms of art that may be used to describe the motion ofsome or all of the fabric items forming the laundry load. However, notall of the fabric items forming the laundry load need exhibit the motionfor the laundry load to be described accordingly. Further, the rotationof the fabric items with the drum 18 may be facilitated by the baffles28.

The motor 30 may be any suitable type of motor for rotating the drum 18.In one example, the motor 30 may be a brushless permanent magnet (BPM)motor having a stator 32 and a rotor 34. Other motors, such as aninduction motor or a permanent split capacitor (PSC) motor, may also beused. The motor 30 may rotate the drum 18 at various speeds in eitherrotational direction.

The washing machine 10 may also include at least one balance ring 38containing a balancing material moveable within the balance ring 38 tocounterbalance an imbalance that may be caused by laundry in thetreating chamber 20 during rotation of the drum 18. The balancingmaterial may be in the form of metal balls, fluid or a combinationthereof. The balance ring 38 may extend circumferentially around aperiphery of the drum 18 and may be located at any desired locationalong an axis of rotation of the drum 18. When multiple balance rings 38are present, they may be equally spaced along the axis of rotation ofthe drum 18.

While the illustrated washing machine 10 includes both the tub 22 andthe drum 18, with the drum 18 defining the laundry treating chamber 20,it is within the scope of the invention for the washing machine 10 toinclude only one receptacle, with the receptacle defining the laundrytreating chamber for receiving the laundry load to be treated.

The washing machine 10 of FIG. 1 may further include a liquid supply andrecirculation system 40. Liquid, such as water, may be supplied to thewashing machine 10 from a water supply 42, such as a household watersupply. A supply conduit 44 may fluidly couple the water supply 42 tothe tub 22 and a treatment dispenser 46. The supply conduit 44 may beprovided with an inlet valve 48 for controlling the flow of liquid fromthe water supply 42 through the supply conduit 44 to either the tub 22or the treatment dispenser 46.

A liquid conduit 50 may fluidly couple the treatment dispenser 46 withthe tub 22. The liquid conduit 50 may couple with the tub 22 at anysuitable location on the tub 22 and is shown as being coupled to a frontwall of the tub 22 in FIG. 1 for exemplary purposes. The liquid thatflows from the treatment dispenser 46 through the liquid conduit 50 tothe tub 22 typically enters a space between the tub 22 and the drum 18and may flow by gravity to a sump 52 formed in part by a lower portionof the tub 22. The sump 52 may also be formed by a sump conduit 54 thatmay fluidly couple the lower portion of the tub 22 to a pump 56. Thepump 56 may direct fluid to a drain conduit 58, which may drain theliquid from the washing machine 10, or to a recirculation conduit 60,which may terminate at a recirculation inlet 62. The recirculation inlet62 may direct the liquid from the recirculation conduit 60 into the drum18. The recirculation inlet 62 may introduce the liquid into the drum 18in any suitable manner, such as by spraying, dripping, or providing asteady flow of the liquid.

A heater, such as sump heater 63 or steam generator 65, may be providedfor heating the liquid and/or the laundry.

Additionally, the liquid supply and recirculation system 40 may differfrom the configuration shown in FIG. 1, such as by inclusion of othervalves, conduits, wash aid dispensers, heaters, sensors, such as waterlevel sensors and temperature sensors, and the like, to control the flowof treating liquid through the washing machine 10 and for theintroduction of more than one type of detergent/wash aid. Further, theliquid supply and recirculation system 40 need not include therecirculation portion of the system or may include other types ofrecirculation systems.

As illustrated in FIG. 2, the controller 14 may be provided with amemory 64 and a central processing unit (CPU) 66. The memory 64 may beused for storing the control software that is executed by the CPU 66 inexecuting one or more cycles of operation using the washing machine 10and any additional software. The memory 64 may also be used to storeinformation, such as a database or table, and to store data receivedfrom one or more components of the washing machine 10 that may becommunicably coupled with the controller 14.

The controller 14 may be operably coupled with one or more components ofthe washing machine 10 for communicating with and controlling theoperation of the component to complete a cycle of operation. Forexample, the controller 14 may be coupled with the user interface 16 forreceiving user selected inputs and communicating information with theuser, the motor 30 for controlling the direction and speed of rotationof the drum 18, and the pump 56 for draining and recirculating washwater in the sump 52.

The controller 14 may also receive input from one or more sensors 70,which are known in the art. Non-limiting examples of sensors that may bycommunicably coupled with the controller 14 include: a treating chambertemperature sensor, a moisture sensor, a weight sensor, a drum positionsensor, a motor torque sensor and a motor speed sensor. Additionally,the sensor may be a physical sensor or may be integrated with the motorand combined with the capability of the controller 14, may function as asensor. For example, motor characteristics, such as speed, current,voltage, torque etc., may be processed such that the data providesinformation in the same manner as a separate physical sensor. Incontemporary motors, the motors often have their own controller thatoutputs data for such information.

The controller 14 may be operably coupled with the motor 30 of thewashing machine 10 for controlling the motor 30 to rotate the drum 18 tocomplete a cycle of operation. The motor 30 may send motorcharacteristic information to the controller 14 that is indicative ofthe applied torque, such as motor current or wattage, as the drum 18 isrotated. The controller 14 may use the motor characteristic informationto determine the torque applied by the motor 30 using software that maybe stored in the controller memory 64. Alternatively, the controller 14may receive input from a motor sensor 68 for monitoring the torqueand/or speed of the motor 30 applied to the drum 18 during a cycle ofoperation. The motor sensor 68 may be any suitable sensor, such as anoptical sensor or a hall sensor in the case of a speed sensor, or avoltage or current sensor in the case of a torque sensor. The motorsensor 68 may be integrated with the motor, such as with the motorcontrol, or it may be separate from the motor.

The previously described washing machine 10 may be used to implement oneor more embodiments of a method of the invention. The embodiments of themethod function to control the duration of an extraction phase of thecycle of operation by rotating the treating chamber 20 at apredetermined/set rotational speed until a there is leveling of themotor torque.

Referring to FIG. 3, prior to describing a method of operation, a briefsummary of the underlying phenomena is useful to aid in the overallunderstanding. FIG. 3 shows the relationship between drum speed duringan extraction profile, motor torque, and liquid remaining in the laundryover time. As can be seen, the extraction profile has multiple speedplateaus 116, 118, 120, where the drum 18 is rotated at a set spinspeed. As the drum 18 is accelerated to each of these plateaus 116, 118,120, greater torque is required to accelerate the rotational mass, whichis a combination of the mass of the drum 18, laundry, and liquidretained in the laundry. Shortly after reaching the plateau 116, 118, or120, the torque required to rotate the drum 18 peaks as at 122, 124, 126and then quickly drops off to an asymptotic phase, where the torque isat a more steady state and trends toward leveling off as at 128, 130,132. The initial quick drop off of torque is attributable to no longeraccelerating the drum 18 in combination with a significant removal ofliquid from the laundry during the acceleration, which reduces the massbeing rotated. The asymptotic drop off of torque is attributable to theremoval of liquid from the laundry load due to the centrifugal forceacting on the laundry load while it is being rotated at the set spinspeed. As can be seen, the asymptotic leveling of the torque correspondsto a similar asymptotic reduction in the liquid retained in the laundryload. Thus, over time, the rate of liquid removal drops as the drum 18is rotated at the set spin speed. At some point, it is no longerbeneficial to continue rotating at the set spin speed because the amountof removed water is so little, especially from an energy consumption andcycle time perspective.

The invention uses the leveling of the motor torque during a plateau116, 118, 120 to trigger the completion of the beneficial liquidextraction for a given plateau 116, 118, or 120. The torque applied bythe motor 30 may be monitored by the controller 14, and when theleveling of the toque is detected, it may be assumed that there is nomore beneficial liquid to be extracted from the laundry at thatparticular set speed. At this point, the controller 14 can determine ifextraction is complete or if more liquid needs to be extracted. If moreliquid needs extraction, the drum 18 is accelerated to another, higher,set spin speed and maintained there to form another speed plateau 116,118, or 120. If extraction is complete, the controller 14 may move on tothe next phase, if any, of the cycle of operation.

FIG. 4 illustrates a flow chart corresponding to a method of operatingthe washing machine 10 using an extraction method 100 based on the abovedescribed phenomena as implemented during the extraction phase of thecycle of operation according on one embodiment of the invention. Theextraction method 100 may be implemented in any suitable manner, such asautomatically or manually, as a stand-alone phase or cycle of operationor as a phase of an operation cycle of the washing machine 10. The cycleof operation may include other individual cycles or phases, such as awash phase and/or a rinse phase, or the cycle of operation may have onlythe extraction method 100. When the cycle of operation includes otherindividual phases, the extraction method 100 may function as anintermediate extraction phase, a final extraction phase, or other typeof extraction phase. Regardless of the implementation of the extractionmethod 100, the extraction method 100 may be employed to extract liquid,which may be water, a combination of water and detergent or other washaid, or other types of fluid, from laundry in the treating chamber 20.The liquid may be imparted to the laundry prior to the extraction method100 in any suitable manner, such as during a wash phase, a rinse phase,a hand-washing process, or other method for imparting the liquid to thelaundry.

The method 100 begins with a first extraction at 102 that comprisesrotating the drum 18 at a set spin speed for an initial extraction ofliquid from the laundry. The initial extraction removes a portion of theliquid from the laundry. The first spin speed defines a first speedplateau, such as plateau 116 of FIG. 3, and is a rotational speedsufficient to apply at least a 1 G centrifugal force on the laundry.

At 104, while the drum 18 is rotating, the controller 14 may monitor oneor more motor characteristic signals, indicative of the motor torque,which as described is a direct output from the motor sensor 68. Othernon-limiting examples of characteristics indicative of motor torqueinclude the motor current and motor voltage. As liquid is extracted fromthe laundry, the mass of the laundry decreases along with acorresponding decrease in the torque required by the motor 30 tomaintain the first spin speed of the drum 18.

At 106, a determination is made as to whether the monitored torque hasleveled off. This determination may be made in several ways. One ofwhich is determining the time rate of change of the motor torque whichshould be a decrease, and comparing it to a threshold. When the timerate of change satisfies the threshold, such as falling below thethreshold value. The threshold value for the time rate of change may beselected in light of the characteristics of a given machine. Thethreshold value may be selected based on balancing liquid removal,energy consumption, and cycle time.

The term “satisfies” the threshold is used here to mean the valuecompared to the threshold or reference value meets the desired criteriaof the comparison because the criteria and threshold values may easilybe altered to be satisfied by a positive/negative comparison or atrue/false comparison.

Alternatively, it is possible to monitor the magnitude of the torqueover time, instead of the time rate of change. For a given load size andtype, tabular threshold data may be developed of the torque required torotate a load of that size and type at a given spin speed. When themagnitude of the torque satisfies the threshold, a leveling may bedeemed to occur.

Once a level is determined at 106, control passes to 110 where adetermination is made regarding whether the extraction is complete. Ifthe extraction is determined to be complete, the extraction cycle endsand control will pass back to the controller 14 to implement the rest,if any, of the cycle of operation. If extraction is determined not to becomplete, the set spin speed is increased and control passes back to 102and a new spin plateau is implemented and the process is repeated. Thisprocess is repeated until the extraction is completed.

Extraction may be completed in a variety of ways. Extraction may becompleted when the set spin speed reaches a predetermined upper limit,which may be a function of load size, load type, and load imbalance.Extraction may be completed based on the residual moisture level in theload. Extraction may be completed after the passing of a predeterminedamount of time or number of extraction phases completed.

A benefit of the extraction method 110 lies in the ability to moreaccurately determine when the beneficial liquid extraction has ceasedfor a given plateau. In prior methods, the plateaus were maintained fora given time period, which was selected to be longer than necessary toensure that all beneficial liquid had been extracted. With the method ofthe invention, the plateau times may be reduced, which leads to improvedenergy consumption and shorter cycle times.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation. Reasonable variationand modification are possible within the scope of the forgoingdisclosure and drawings without departing from the spirit of theinvention which is defined in the appended claims.

What is claimed is:
 1. A laundry treating appliance, comprising: arotatable treatment chamber in which the laundry is received fortreatment; a motor coupled to and rotating the treatment chamber; amotor torque sensor outputting a torque signal indicative of the motortorque; and a controller having an extraction program comprising aplurality of executable instructions stored in a memory of thecontroller, and the controller operably coupled to the motor andreceiving the torque signal such that the controller controls the motorto implement the extraction program by rotating the treatment chamberthrough multiple, sequentially increasing set spin speeds, which are atleast a speed sufficient to satellize laundry in the treatment chamberat each of the set spin speeds, which results in a correspondingconstant speed plateau where the treating chamber is rotated at aconstant speed for the corresponding set spin speed to definesequentially increasing constant speed plateaus, ceasing thesequentially increasing speed plateaus when the set spin speed reaches apredetermined upper limit, monitoring the torque signal indicative ofmotor torque during the speed plateaus, determining from the monitoringwhen the time rate of change of the torque signal falls below apredetermined time rate of change threshold value, and sequentialadvancement from a current one of the speed plateaus to the next one ofthe speed plateaus is triggered when the time rate of change of thetorque signal falls below the predetermined time rate of changethreshold value for the current one of the speed plateaus.
 2. Thelaundry treating appliance of claim 1 further comprising a rotatabledrum defining the treatment chamber.
 3. The laundry treating applianceof claim 2 wherein the drum is rotatable about at least one of ahorizontal axis or vertical axis.
 4. The laundry treating appliance ofclaim 2 wherein the drum is perforated.
 5. The laundry treatingappliance of claim 2 further comprising a tub in which the drum isrotatably mounted.
 6. The laundry treating appliance of claim 1 furthercomprising a motor speed sensor outputting a speed signal indicative ofthe rotation speed of the motor, and wherein the controller is operablycoupled to the motor and receiving the speed signal.
 7. The laundrytreating appliance of claim 6 wherein the controller is furtherconfigured to control the motor to implement the extraction program bymonitoring the speed signal indicative of the rotational speed of themotor during the speed plateaus, determining from the monitoring whenthe time rate of change of the speed signal satisfies a speed thresholdvalue and the time rate of change of the torque signal falls below thepredetermined time rate of change threshold value, and sequentialadvancement from a current one of the speed plateaus to the next one ofthe speed plateaus is triggered when the speed threshold value issatisfied and the time rate of change of the torque signal falls belowthe predetermined time rate of change threshold value.
 8. The laundrytreating appliance of claim 7 wherein the motor speed sensor is part ofthe motor.
 9. The laundry treating appliance of claim 1 wherein themotor torque sensor is part of the motor.
 10. The laundry treatingappliance of claim 1 wherein the motor torque sensor comprises a motorcurrent sensor or a motor voltage sensor.
 11. The laundry treatingappliance of claim 1 wherein the controller is further configured tocontrol the motor to implement the extraction program by determining aleveling of a motor characteristic indicative of motor torque when thetime rate of change of the torque signal falls below the predeterminedtime rate of change threshold value.
 12. The laundry treating applianceof claim 11 wherein the controller is further configured to control themotor to implement the extraction program by monitoring the leveling ofthe motor characteristic when a magnitude of the motor characteristicsatisfies a motor characteristic threshold value.
 13. The laundrytreating appliance of claim 1 wherein the controller is furtherconfigured to control the motor to implement the extraction program byaccelerating the rotation of the treating chamber between each of thespeed plateaus.
 14. A laundry treating appliance, comprising: arotatable treatment chamber in which the laundry is received fortreatment; a motor coupled to and rotating the treatment chamber; amoisture sensor outputting a moisture signal indicative of the residualliquid retained in the laundry; a motor torque sensor outputting atorque signal indicative of the motor torque; and a controller having anextraction program comprising a plurality of executable instructionsstored in a memory of the controller, and the controller operablycoupled to the motor and receiving the moisture signal and the torquesignal such that the controller controls the motor to implement theextraction program by rotating the treatment chamber through multiple,sequentially increasing set spin speeds, which are at least a speedsufficient to satellize laundry in the treatment chamber at each of theset spin speeds, which results in a corresponding constant speed plateauwhere the treating chamber is rotated at a constant speed for thecorresponding set spin speed to define sequentially increasing constantspeed plateaus, ceasing the sequentially increasing speed plateaus whenthe moisture signal indicative of the residual liquid retained inlaundry satisfies a residual liquid threshold, monitoring the torquesignal indicative of motor torque during the speed plateaus, determiningfrom the monitoring when the time rate of change of the torque signalfalls below a predetermined time rate of change threshold value, andsequential advancement from a current one of the speed plateaus to thenext one of the speed plateaus is triggered when the time rate of changeof the torque signal falls below the predetermined time rate of changethreshold value for the current one of the speed plateaus.
 15. Thelaundry treating appliance of claim 1 wherein the motor torque sensorcomprises a motor current sensor or a motor voltage sensor.
 16. Thelaundry treating appliance of claim 1 wherein the controller is furtherconfigured to control the motor to implement the extraction program bydetermining a leveling of a motor characteristic indicative of motortorque when the time rate of change of the torque signal falls below thepredetermined time rate of change threshold value.
 17. The laundrytreating appliance of claim 16 wherein the controller is furtherconfigured to control the motor to implement the extraction program bymonitoring the leveling of the motor characteristic when a magnitude ofthe motor characteristic satisfies a motor characteristic thresholdvalue.
 18. A laundry treating appliance, comprising: a rotatabletreatment chamber in which the laundry is received for treatment; amotor coupled to and rotating the treatment chamber; a motor torquesensor outputting a torque signal indicative of the motor torque; and acontroller having an extraction program comprising a plurality ofexecutable instructions stored in a memory of the controller, and thecontroller operably coupled to the motor and receiving the torque signalsuch that the controller controls the motor to implement the extractionprogram by rotating the treatment chamber through multiple, sequentiallyincreasing set spin speeds, which are at least a speed sufficient tosatellize laundry in the treatment chamber at each of the set spinspeeds, which results in a corresponding constant speed plateau wherethe treating chamber is rotated at a constant speed for thecorresponding set spin speed to define sequentially increasing constantspeed plateaus, ceasing the sequentially increasing speed plateaus aftera predetermined number of advancements, monitoring the torque signalindicative of motor torque during the speed plateaus, determining fromthe monitoring when the time rate of change of the torque signal fallsbelow a predetermined time rate of change threshold value, andsequential advancement from a current one of the speed plateaus to thenext one of the speed plateaus is triggered when the time rate of changeof the torque signal falls below the predetermined time rate of changethreshold value for the current one of the speed plateaus.
 19. Thelaundry treating appliance of claim 18 wherein the motor torque sensorcomprises a motor current sensor or a motor voltage sensor.
 20. Thelaundry treating appliance of claim 18 wherein the controller is furtherconfigured to control the motor to implement the extraction program bydetermining a leveling of a motor characteristic indicative of motortorque when the time rate of change of the torque signal falls below thepredetermined time rate of change threshold value.